The Use of Nano-Particles to Produce Iridescent Metallic Effects on Ancient Ceramic Objects

Nano-sized materials have been often used in the past to realize objects with particular characteristics. One of the most outstanding examples is represented by luster pottery, showing shining surfaces with particular optical properties. Luster was one of the most sophisticated technique for the decoration of majolicas. It consists of a thin metallic film contg. silver, copper and other substances, like iron oxide and cinnabar, applied in a reducing atm. on a previously glazed ceramic. In such a way, beautiful iridescent reflections of different colors (in particular gold and ruby-red) are obtained. This technique, at first developed in Iraq, was introduced in Italy from Spain. In Italy the potters of the two centers of Gubbio and Deruta, in central Italy, became so expert that nowadays modern artisans are not able to reproduce the wonderful effects obtained during Renaissance. A complete characterization by means of numerous techniques has been carried out on a great no. of shards and precious work of arts conserved in many important museums. This allowed to draw some correlations between the prepn. technique and the obtained nano-structure.